In a standard SAP system, executables (program files) are stored in a single executables directory. The name of this directory is operating-system specific.
After a standard installation with several instances in a homogenous SAP system, the executables are located in a directory on a central server (host or host system). Normally, it is the host on which the central instance of the SAP system was created. Normally, additional dialog instances are also installed on other hosts. These distributed SAP instances use the central executables directory together over your network using NFS.